Yet for Jared Harris, who stars as the ailing King George VI in the opening episodes, rumours that the royal family are nervous about the series are of little concern.

“I think Netflix are putting those stories out there,” he said. “They want to say that Buckingham Palace has Netflix – it’s everywhere including the palace! There’s so much written about them, but I think this would be a good one for them to watch because it’s very empathetic.”

There are winning turns throughout the cast, but as far as Jared – who played English character Lane Pryce in AMC’s hit drama Mad Men – is concerned, Peter Morgan’s script is what marks it out in the crowded period drama genre.

“Normally characters end up being drawn just to support the point of view of your main character,” he said. “They’re not fully realised, but this script was very different. Each character is unique and has a function. The last time I read scripts like that was on Mad Men!

“But The Crown is very different in the sense that the directors had a lot of freedom,’ he explained. “They were encouraged to collaborate and participate… a lot of scenes were invented by directors. That certainly never happened on Mad Men!”

The first series of The Crown is already Netflix’s biggest ever production and a second is already filming, but rather than feeling the pressure of such a hefty budget Jared said it allowed the cast extra freedom.

For an actor who has starred in blockbuster films such as Sherlock Holmes and Lincoln, working on projects with big budgets isn’t out of the ordinary…

“We weren’t trying to shoot 10 pages a day, which takes a lot of pressure off the actors,” he said. “In that sense, The Crown is like a movie – or 10 movies. On Mad Men we were shooting seven pages a day, on a movie maybe you’re doing three a day and on giant movies half a page or something crazy like that…

“On this, some days we did five and on one day we shot an eighth of a page, you know… that was because we had a film director [Stephen Daldry] in charge and he understood the story he wanted to tell.”

While the millions of pounds involved didn’t bother him, Jared admitted that it took a while before he got used to following in the footsteps of Colin Firth, who won an Oscar for his portrayal of George VI in The King’s Speech.

“Most of what I knew of George VI was from watching The King’s Speech!” he explained. “Was it in my mind every single day, in the beginning? Well, they shot The Crown at Elstree—which is where they shot The King’s Speech. And there was this massive, massive 60ft poster of that movie, with a 40ft image of Colin Firth as King George VI. I would walk past him every single day, and he’d be looking down on me. In the beginning, I resented it.

“But after a few weeks I remember walking past that poster and going, ‘You know what? He doesn’t look anything like him either. And that didn’t bother anybody! It doesn’t matter! It’s fine! It’s interpretation, not impersonation, you know?’ So thank you, Colin.’